Preheat your oven to 325 degrees.,Spray an 8 in square pan with cooking spray and line it with parchment paper.,Then spray the paper.,Crush cookies and press into bottom of pan.,Using a food processor, blend cream cheese and sour cream until smooth.,Then add cocoa, cornstarch, sugar, and both eggs.,Process until smooth.,Pour the mixture into the pan and top with chocolate chips.,______,Then let cool in the pan.,Refrigerate for at least an hour, then tip out onto a cutting board, flip over and cut.